It is the specific aim of this research to develop, study and apply chemical procedures to the modification of proteins for food use to improve their functional properties and nutritional quality. The program will be a long range one which will have as its fundamental basis a study of the chemistry of the different side chains of the amino acids in proteins and, more particularly, the effect of different chemical reactions on the side chains. The main purpose is to develop reagents and methods to chemically modify these side chains so as to form proteins with physical and nutritional properties more suitable for foods. This research proposes to modify proteins so as to (a) stabilize structure to decrease solubility or improve texture, (b) increase solubility, (c) increase water absorbing and/or gelling capacities, (d) increase susceptibility to denaturation on foaming or heating. The research will also deal with nutritional quality of the modified proteins including changes in digestibility and availability of modified amino acids and toxicity of the products. Reversible blocking agents that can be removed by acid or enzymatic hydrolysis in the stomach will be investigated.